It is a truism that Calvinism was the most internationally vibrant of the Protestant creeds that emerged from the Reformation. From Eastern Europe to colonial North America, Calvinism spread quickly across the early modern world and, as such, has been examined as a global phenomenon, most recently by Phil Benedict in his broad survey Christ's Churches Purely Reformed (Yale, 2002). We know much about Calvinism in its various settings, but there are some regions, however, where our understanding has been more limited. The growth and development of the Reformed faith in Eastern Europe, more specifically within the Polish and Lithuanian lands, is one of those areas. R. J. W. Evans once famously quipped that Calvinism spread quickly and bloodlessly across East Central Europe, but also anemically. Evans’ assessment has contributed to some of the general stereotypes we have of Calvinism in the region; a picture of a faith that expanded rapidly but with a few notable exceptions disappeared in just a few generations. Kazimierz Bem's fine monograph, Calvinism in the Polish Commonwealth, challenges some of these stereotypes, and though his study is idiosyncratic, even quirky at some junctures, it presents the fullest, clearest, and most comprehensive study of the Reformed faith in the Polish-Lithuanian Commonwealth available to an Anglophone audience today.

Bem's accomplishments are many. Here, I will highlight three of his most important. In systematic fashion he lays out the geography of the church. He focuses on three separate Reformed churches in the Polish-Lithuanian Commonwealth, which eventually draw closer together into a Calvinist union. He begins with the Czech Brethren, an emigrant church that established itself in Greater Poland in the middle of the sixteenth century. To the south in Little Poland, a Calvinist church began to emerge in the second half of the sixteenth century, while at about the same time in Lithuania a third Reformed body began to organize itself. These churches had their separate traditions and histories came together in 1634 (Włodowa General Convocation) with the publication of a single hymnal and common liturgy while efforts were additionally made to harmonize their governing structures.

As he details the growth and establishment of the Commonwealth's Reformed church, Bem also addresses the enduring stereotype of Calvinism's rapid rise but even more precipitous fall in the Polish and Lithuanian lands. Admittedly, there is some truth to this simple narrative. Many nobles did convert quickly to Calvinism only to have the next generation return to Catholicism. But not all, and there were others outside the nobility who remained with the Reformed. Indeed, one of Bem's most important achievements is his explanation of Calvinism's remarkable staying power within the Commonwealth. Here, he points to families and patron networks that contributed to the spread of the faith. He also highlights the development of “clerical dynasties” (125) that provided the church with pastors up to the middle of the twentieth century. Bem is at his best tracing these complicated social networks that were at the heart of Polish Calvinism and the most important element of the church's success and survival.

Finally, Bem's study sheds a very welcome light on the social history of religion in the Commonwealth. His book condenses and encapsulates a remarkable body of research. He has carefully worked through archives, ecclesiastical chronicles, synodal records, memoirs, and other sources to present a fascinating picture of religious life in this period. We learn of one seventeenth-century pastor brought up before a church synod on a variety of charges including armed robbery, espionage for the Ottomans, abandonment of his wife, the impregnation of a servant girl, and then her attempted murder. While this pastor was successfully excommunicated, there are also dramatic stories of failed church discipline. When the magnate Łukasz Górka participated in the murder of his wife's first husband in 1554, the Czech Brethren, the church to which he belonged, ordered that he publicly repent. Górka simply ignored them and decided to join the Lutherans who were evidently more tolerant of such behavior with the high nobility.

From marriage, family life, divorce, and adultery to education and book culture, Bem offers a broad survey of everyday life among the Commonwealth's Calvinists.

Calvinism in the Polish Lithuanian Commonwealth can, however, be challenging for those unfamiliar with the region and its history. Bem assumes much from his audience. In the book's first paragraph, he refers to the three Reformed churches of the Commonwealth without explanation. On the first page, readers encounter references to the Sandomir Consensus and the Confederation of Warsaw. Sadly, there are Reformation specialists who would be unable to identify these terms. Though he does provide a brief overview of the Reformation in Poland and Lithuania before 1548 alongside other introductory material, many readers will need to work through this volume slowly and carefully. There are a series of maps, a timeline, and illustrations that certainly do help as navigational aids. The effort is well worth it. For anyone serious about the world of Polish Calvinism, this book will be indispensable.